Compact, light and durable bobbin



J. H. ALEXANDER ET AL 3,408,023

COMPACT, LIGHT AND DURABLE BOBBIN 3 Sheets- Sheet 1 Oct. 29, 1968 Filed April 4., 1966 ATTORNEY Fl'g.

1968 J. H. ALEXANDER ET AL COMPACT, LIGHT AND DURABLE BOBBIN 3 Sheets-Sheet 5 Filed April 4, 1966 ATTORNEY United States Patent 3,408,023 CGMPACT, LIGHT AND DURABLE BOBBIN James H. Alexander and Beryl A. Boggs, Chester, Va., assignors to Allied Chemical Corporation, New York, N .Y., a corporation of New York Filed Apr. 4, 1966, Ser. No. 539,713 11 Claims. (Cl. 242-11831) This invention relates to textile bobbins and more specifically to bobbins to be mounted on and driven by vertical spindles. Still more specifically, this invention is directed to compact, lightweight, durable, high capacity bobbins having heads for retaining the square-ends of a yarn package.

The yarns in a draw-twister machine are mechanically wound on these bobbins normally under tension. The sum total of these tensions on successive windings causes considerable radial stresses on the cylindrical barrel and axial forces On the heads which tend not only to create a lengthening of the barrel due to the stresses, but also a distortion of the heads. These bobbins, especially for the larger packages produced on the modern high-speed draw-twisters, must, therefore, be made stronger and also lighter than any of the presently available bobbins.

Moreover, it is essential that the structure of the bobbins be maintained as simple as possible for easy assembly, with separate heads for quick replacement when necessary so that the entire bobbin does not have to be discarded, if the heads are damaged, or remain out of service for any length of time. It has been found that the bobbins made in accordance with this invention have these advantages and are capable of having wound thereon a load of yarn almost twice the amount normally wound on the presently available bobbins or spools.

More specifically, in many instances of the prior art, yarn was withdrawn from or fed to a bobbin axially over one end thereof past a head with a rounded, smooth, peripheral edge. The spools or bobbins adapted for this type of use have been made with removable heads with means for easily securing them to the upper-end of the tubular barrel forming the portion of the spool which receives the yarn windings. Thus, when the rounded edges of a head are accidentally scarred or roughened causing the yarn to snag or break from engaging said rough spots, or if the head at the lower-end of the barrel was damaged in any way, either of the heads may be easily replaced instead of having to discard the entire bobbin. In many of the prior art bobbins, however, the means for securing the head to the end of the barrel took many different forms, all of which involved an unnecessary and excessive amount of material in order to provide the required structural strength for the barrel against high collapsing stresses caused by the shrinking of a yarn package. In addition, it was necessary to have a required strength in the head members suthcient to withstand the stresses of the ends of a square package of stretched yarn directed axially against the inner faces of said heads.

In attempts to accomplish these results, some of the prior art, e.g., U.S. Patent Nos. 2,610,811 and 2,837,297, used internal rib structures to reinforce the barrel against the high collapsing stresses, with full length sleeve structures to provide added tensile strength for holding the heads against high axial stresses. Still other prior art, e.g., Patent No. 2,690,885, relied on the use of a full-length sleeve inside a heavy barrel structure with narrow flanges on the head-securing sleeve. This, however, provided little reinforcement to the head against deformation due to the axial stresses of the ends of the yarn package on the inner faces of said head.

More specifically, typical examples of the cumbersome and heavy construction of bobbins that have 3,408,023 Patented Oct. 29, 1968 been devised in the past to meet the tremendous stress requirements in large capacity high-speed bobbins may be further illustrated by other prior art. For example, in many instances the barrel was mounted upon a center tube engaging a spindle, the center tube being in the form of a hollow bolt passing through the barrel, with nuts at each end threaded into the center tube and designed so as to restrain any elongation of the barrel. Thus, the center tube served to resist the forces on the barrel and maintain the overall length substantially constant notwithstanding any changes due to the forces to which the bobbin may be subjected. It was found, however, that this type of construction as not sufliciently strong to withstand the high axial stresses of a full package of stretched yarn without having to make the bobbin too heavy and cumbersome for high-speed operations and ease of handling in close quarters.

The new bobbins of this invention, however, were found to be capable of withstanding the high-strength and high-speed requirements in spite of a considerable reduction in weight and a much simpler construction. In addition, the new bobbins provide a savings on material and Weight, while increasing the strength of the structure by providing a simple, light, barrel and head combination of minimum thickness with skeletonized reinforcements. These reinforcements were used only where needed and served some other purpose in addition to reinforcing the basic combination of the bobbin.

The relative importance and construction of the bobbins of this invention can be appreciated when the drawtwister machinery on which the bobbins are to be used and its functions are understood. Thus, the draw-twister, basically, has two functions, (1) to stretch the yarn causing it to crystallize and orient the crystallit'es and (2) to twist the yarn and thereby collect the filaments on a compact bundle. Yarn, such as nylon for example, is commonly processed into packages with an apparatus known in the art as a draw-twister whereon the yarn is stretched to a multiple of its original length and wound onto a package under tension while simultaneously being twisted.

The yarn is supplied at a constant speed by a feed roll to a draw roll which rotates at a higher speed so as to draw the yarn. The yarn then travels directly to a ringtwister which winds the yarn under tension on the bobbin. The ring-twister comprises a vertical spindle, the bottom portion of which is supported by a bolster, a whorl mounted on the spindle above the bolster, a portion of the spindle adapted to hold the bobbin, a traveler-guide slidably supported on the ring to guide the yarn onto the bobbin, and means for moving the ring up and down to build the yarn package on the bobbin. To produce the twist, the traveler revolves about the bobbin at a lower annular velocity than that of the bobbin. This forces the traveler to rotate and impart twist to the yarn. Twists on most nylon yarns, for example, run from about 0.5 to 0.1 turn per inch.

Thus, to accommodate the draw-twister in preparing packages of yarn, it is necessary to have a bobbin capable of withstanding the high stresses, particularly in preparing packages of heavy denier yarn weighing as high as twenty pounds. This has been accomplished by utilizing the bobbins of this invention.

Accordingly, to avoid the heavy construction of the available bobbins and to provide a bobbin capable of withstanding the stresses of yarn mechanically wound thereon, the structure of the bobbins of this invention and the advantages thereof will become apparent from a further and more detailed description as follows:

Thus, it is an object of this invention to provide bobbins having reduced bulk and weight while at the same 3. time having increased strength, as replacement of parts.

It is another object of this invention to provide an axially extending reinforcing rim on the periphery of a flange of a head-securing sleeve which serves not only as a shield over the top of a waste collar at the base of a drive spindle, on which the bobbin is mounted, but also prevents the yarn from entering the space between the waste collar and the flange and, therefore, avoids any lifting ofthebobbin from the spindle.

It is another object of this invention to provide a lightweight skeletonized bearing-bushing in the barrel of the bobbin for reinforcing said barrel in addition to providing a bearing for the top of the drive spindle.

It is still another object of. this invention to provide a bobbin having a centered polygonal socket or key in the sleeve portion of the head-securing flange in the lower-end of the barrel which fits over a correspondingly formed driving dog or key in the base of the spindle. I

It is still a further object of this invention to provide a centering bushing in said sleeve portion above said socket or key groove' to fit over a corresponding enlarged stepped portion of a spindle above said driving dog or key.

It is still a further object of this invention to provide a high-strength bobbin capable of carrying a squareend package of yarn which is economical to manufacture and easy to repair or replace its parts.

These and other objects of the invention will become apparent from a further and more detailed description of the invention, as illustrated in the accompanying drawings, wherein:

FIGURE 1 is a sectional view of one form of bobbin made in accordance with this invention.

FIGURE 2 is an end view taken from the top of this bobbin.

FIGURE 3 is a bottom view thereof.

FIGURE 4 is a detailed sectional view of the base portion of this bobbin mounted on a drive spindle, the corresponding portion of which is shown in section.

FIGURES 58 are similarly corresponding views of a modified form of bobbin, having an enlarged bearing sleeve above the drive dog socket in its base to fit over a stepped portion of the spindle above the drive dog.

FIGURES 9-12 are corresponding views of another modification of the present type of bobbins with a skeletonized upper spindle bearing sleeve, a one-piece upper flange sleeve lift knob for holding the upper head fixed to the barrel, and a diametrical key groove in the base plate to fit over a drive key at the base of the spindle.

well as the ease of Th structure shown in FIGURES 1-4 comprises a lightweight barrel 10 preferably made of high-strength aluminum alloy, internally threaded at both ends, to re ceive the headsecuring sleeves l2 and 14 at the upper and lower-ends, respectively, the head 16 being held against the upper-end and the head 18 being held against the lower-end. Preferably, these securing-sleeves may be made of the same aluminum alloy or any other type of metal. Likewise, the heads may be made of lightweight materials, including metal and plastic, but preferably comprise a phenolic laminate including, for example, a laminate of paper and/or wood with a phenolic resin.

The upper-head 16 is removably fixed to the outer end of sleeve 12 by means of screws 20, and a lift knob 22 is set into a counterbore 24 in the outer face of the head 16 and is fixed to the sleeve 12 by means of screws 26 passing through bores 28 in the head. The head 16 and lift knob 22 may be made of a suitable light, plastic material including, for example, phenolic resins and laminates of the phenolic resins with paper and/or wood and similar materials. Screws 26 have their heads sunk in deep counterbores 30 which may be used for receiving the pins of a special spanner wrench for tightening the sleeve and head assembly against the end of the barrel 10, which may be provided with a thin felt washer 32 to 4 frictionally substantially lock the joint against accidental loosening when the assembly is firmly tightened thereon.

A force fit plug 34 supporting a bushing 36 made of bronze, plastic or other bearing materials, provides a hearing for the upper-end of a spindle'mounted inside the barrel 10. This plug in addition reinforces the barrel 10 against crushing stresses distributed over the entire length thereof by reducing the length of its unsupported spans to substantially half of its full length. The lower sleeve 14 is an annularly flanged element having a base flange 33 which is countersunk into the outer surface of the head 18, which likewise may be made of metal, plastic, and more preferably of phenolic resins and laminates of the phenolic resins with paper and/or wood, etc. The flange 38 has an axially extending rim 40 around its periphery adapted to overlap the top of a waste collar 41 at the base of a spindle on which it is to be mounted. The rim 40 thus not only reinforces the base flange 33 against distortion particularly at its outer edge where the peripheral leverage of the annularly distributed axial stresses is greatest, but also serves as a shield against any yarn from entering the space 39 under the base flange over the top 43 of the waste collar 41 and thus raising the bobbin off the drive means at the base of the spindle. Any such raising of the bobbin obviously may be very dangerous, particularly at the normally high speeds of operation of the spindle on modern draw-twisters.

The sleeve 14 is formed internally to. provide a substantially hexagonal socket with three fiat sides 42 symmetrically spaced at intervals about the axis of the bobbin. These flat faces are adapted to fit with close tolerance over a drive dog 45 at the base of the spindle having similarly formed three outer faces 49. A flange or ridge 44 extends downwardly from the sleeve 14 to provide a conically bevelled guide entrance 46 into the drive socket to facilitate guiding the drive dog 45 thereinto when mounting the bobbin on a drive spindle. This ridge 44 also forms a stop for the bobbin, when mounted, againsLthe top of the shoulder 47 at the base of the drive dog 45.

A conical bevel 48 is provided in the lower end of plug 34 for facilitating .the entry of the upper-end of the spindle into the bushing 36 during completion of the mounting operation.

It is obvious that the flange 38 may be extended radially outwardly to approximately half-way or more of the radius of the head 18, but for practical purposes there are no substantial advantages in extending said flange beyond the rim 40, as shown in the drawings. The circular head 18 may bemade of materials other than plastics and may include, for example, suitable lightweight metal, such as aluminum .and its alloys, but more preferably is prepared from phenolic resins including laminates of paper, woodv and combinations thereof with phenolic resins. Likewise, the sleeve.14,'for practical purposes, can be made of a suitable lightweightmetal but may comprise-plastic or other suitable materials. Thus, while metal is preferred forthe high-stress bobbins, the sleeve may be made of plastic particularly where it is used on bobbins of smaller packages which are not subjected to as much stress.

It should be noted in the drawings in FIGURE 4 which shows thebobbin mounted on the drive spindle (resting on the waste collar) that, in fact, the flange 38 does not rest onthetop 43 of the waste collar 41. Instead, it is preferred to have the rim 44 seated on the shoulder 47 at the base of the spindle, since any inaccuracies in machining or burrs located at the top 43 of the waste collar 41 would tend to cause the bobbin to be cocked on the spindle. In other words, if the flange 38 were resting on the outer edge portion 43 of the waste collar instead of having the rim 44 resting on the shoulder 47, inaccuracies at this greater radius would produce more cocking than that which might be due to inaccuracies at the point where the rim 44 rests on the shoulder 47.

It is also obvious, although not a preferred embodiment, that in some instances it may be desirable to provide the sleeve 14 and head 18 as an integral element. This integral element would be particularly useful in the smaller bobbins where less stress is encountered during the draw-twisting operation.

FIGURES 5-8 illustrate a modification comprising a similar construction as shown in the first four figures except for some minor details in the lift knob assembly 12-16'22 wherein the screws 20 are mounted at the outer edge of the sleeve 12', and the top of the lift knob has a circular groove 50 with a key slot 52 for receiving a correspondingly formed wrench head for turning this assembly in the barrel.

The plug 54 has a bushing 56 made of bronze or other similar material which may be knocked out through either end of the plug for replacement, there being no shoulder in the plug bore at either end against which the plug is installed, as there is in its lower-end, as shown in FIGURE 1. The lower-end of the bushing 54 is bevelled inwardly at 58 substantially in continuation of the plug bevel 48'.

The sleeve 60 at the lower-end has a bushing 62 made of bronze or other similar materials above the drive socket, with an inside diameter equal to that of a circle inscribed in the three flat faces 42 of the socket. This bushing provides a guide bearing 64 for an enlarged stepped base portion 65 of the spindle above the drive dog 45.

Another modification of this invention is shown in FIGURES 9-12 which has the same form of barrel 10. The rest of the elements are simplified and further lightened without sacrificing strength.

The upper sleeve and lift knob are made in a single piece 70, preferably of a light metal but obviously can be made of any other suitable material. The piece 70 has a large bore with axially grooved keyways 72 for engagement by a keyway wrench for turning the lift knob, to loosen or tighten it on the upper end of the barrel, when removing or replacing the head 66. The head 66 is normally held against the end of the barrel by a shoulder flange 68 formed around the outside of the sleeve above its threaded portion.

A thin felt washer 32 may be used between this shoulder flange and the end of the barrel, in a manner similar to that set forth in the other modifications of this invention as described above.

The plug 74 in the middle of the barrel 10 is skeletonized to reduce its weight without sacrificing strength, by cutting away a peripheral groove 76 around its middle portion. The bushing 78 comprising bronze or other similar material is force-fit into plug 74 against a shoulder 80 and is bevelled at its other end 82 in continuation of the conical bevel 88 in the lower-end of the plug. The lower head-securing sleeve 84 has a bushing 86 comprising bronze or other suitable material set in it against a shoulder 99 at its upper-end, to serve as a bearing for an enlarged stepped base portion 87 of the spindle on which it is to be mounted. The lower-end of the bushing 86 may be conically bevelled inwardly to facilitate guiding the spindle and its base portion thereinto. The sleeve 84 further has a wide base flange 92 set into a correspondingly wide counterbore in the lower face of the lower head 94. The flange 92 has a downwardly extending peripheral rim 96, and a rim 98 bevelled on the inside into the bore provided for the bushing 86. The rim 98 has a diametrical drive groove 100, which fits over a drive dog, preferably comprising a pair of stud heads 89 on the top of the shoulder 47. At the bottom of the enlarged stepped portion 87 at the base of the spindle on Which it is to be mounted, the rim 96 fits over the top of a waste collar 41 mounted on said spindle.

An important feature of this invention is that the ordinary annular screw arrangement for securing the upper head to the upper sleeve is supplemented in the first two modifications illustrated herein in FIGURES l-8 by additional annularly arranged screws securing the knob to the sleeve, the lift knob having a continuous shoulder pressing evenly all around the outer face of the head. This provides great strength to the head against rupture, evenly all around, and not merely in the areas immediately adjacent each individual screw securing the heads to the bobbin assemblies as taught in the prior art.

Thus, it has been found that this supplemental support provided evenly all around the head, prevents any warping in spite of the high-stresses caused by a package of stretched yarn on the bobbin. Moreover, the heads will not become deformed or fractured as readily in comparison to utilizing the prior methods of securing them to the bobbin, wherein in some instances the only means was an annular series of screws.

In the third modification illustrated herein in FIG- URES 9-12, the same improvement is obtained by utilizing a one-piece construction of sleeve and lift knob with an exterior shoulder holding the head in a continuous area all around the sleeve. A still further improvement in this respect is found in the securing-sleeve construction for a large head as shown at the lower end of the present bobbin. This securing-sleeve has a wide flange reinforcing head extending radially outwardly from the periphery of the barrel a considerable distance, over a large annular area of the head evenly all around the sleeve. This sleeve is preferably made of a light metal similar to that of the barrel to provide the required strength with a minimum amount of weight. The wide flange may be very light without sacrificing strength, by making it relatively thin except at its periphery, where it is provided with a rim extending downwardly, thus greatly increasing the rigidity at the outer edge of the flange, for added strength against distortion of the head due to the axial stresses of the larger packages.

While this invention has been described with respect to a number of specific embodiments, it is obvious that there are other variations and modifications which can be resorted to without departing from the spirit and scope of the invention, as particularly pointed out in the appended claims.

What is claimed is:

1. A compact, light and durable bobbin comprising a thin walled cylindrical barrel, a circular head having a central aperture with a diameter at least equal to the inside diameter of the barrel and being held against at least one end of said barrel, an annularly flanged element held against the outside of said head and having a rigid sleeve portion extending through the central aperture of the corresponding head with said sleeve portion firmly and directly fixed, by interfitting means, to the inside of said end of the barrel, said annular flange having an outer diameter substantially greater than said barrel to reinforce said head against rupture by high stresses of the ends of a full square package of stretched yarn against said head, said outer diameter of said annular flange having an outwardly extending rim forming an overlap over the top of a waste collar at the base of a spindle when the 'bobbin is mounted thereon.

2. The bobbin as defined in claim 1 further characterized in that said sleeve portion is formed internally as a socket to fit over a correspondingly formed drive dog at the base of its mounting spindle.

3. The bobbin as defined in claim 1 further characterized in that said sleeve portion is formed internally to provide a socket to fit over a correspondingly formed drive dog at the top of said waste collar.

4. The bobbin as defined in claim 1, a second circular head having a central aperture with the diameter substantially equal to the inner diameter of said barrel and being held against the other end of said barrel, a lift knob having a sleeve portion extending through said central aperture and directly fixed firmly to the inside of the other end of said barrel, said lift knob sleeve portion having an external flange held against the outer face of 7 said second head, said sleeve portion fixed to said one end of the barrel being extended outwardly to form a circular ridge with a diametrical drive keyway adapted to fit over a correspondingly formed drive dog in the top of said waste collar.

5. The bobbin as defined in claim 4 further characterized in that a reinforcing plug is mounted substantially in the middle of said barrel and has a bore with a bushing mounted therein to provide a bearing for the upper end of said spindle. 1

6. The bobbin as defined in claim 5 further characterized in that said plug is skeletonized for minimum weight by having a large circular groove around its middle portion cut away.

7. The bobbin as defined in claim 6 further characterized in that said sleeve portion in the lower end of the barrel has a bushing mounted therein to provide a bearing for an enlarged stepped base portion of the spindle above said waste collar.

. S. The bobbin as defined in claim 1 further characterizcd as comprising a second circular head with a central aperture smaller than the inside diameter of said barrel and being held against the end of said barrel, a securing sleeve threaded in the other end of said barrel, said second head being fixed to the outer end of said sleeve and an annularly formed lift knob having screws fixing it to said sleeve through said head, said lift knob being set into a counterbore in the outer face of said head and having a shoulder firmly held against said outer face of the head to hold it against the end of said barrel.

9. The bobbin as defined in claim 1 further characterized in that said circular head comprises a suitably light and strong plasti material, and said barrel and annularly flanged element comprises a suitably light. and strong metal.

10. The bobbin as defined in claim 9 further characterized in thatsaid plastic material is a phenolic laminate.

11. The bobbin as defined in claim 10 further characterized in that said metal is an aluminum alloy.

Reterences Cited UNITED STATES PATENTS 936,526 12/1909 Evans 242-11862 2, 37,297 6/1958 Moss 242-118.62 3,099,417 7/1963 Portal 242-41862 1,857,599 5/1932 Mack 242-l18.61 2,228,475 1/1941 Moyer 242-41832 2,610,811 9/1952 Moss 242-11 61 2,622,825 12/1952 Faris 242 118.61 2,626,764 1/1953 Dunlap 242 118.61 2,690,885 10/1954 Crooks 242118.62 3,132,817 5/1964 At'woodetal. 242118.3X

GEORGE F. MAUTZ, Primary Examiner. 

1. A COMPACT, LIGHT AND DURABLE BOBBIN COMPRISING A THIN WALLED CYLINDRICAL BARREL, A CIRCULAR HEAD HAVING A CENTRAL APERTURE WITH A DIAMETER AT LEAST EQUAL TO THE INSIDE DIAMETER OF THE BARREL AND BEING HELD AGAINST AT LEAST ONE END OF SAID BARREL, AN ANNULARLY FLANGED ELECMENT HELD AGAINST THE OUTSIDE OF SAID HEAD AND HAVING A RIGID SLEEVE PORTION EXTENDING THROUGH THE CENTRAL APERTURE OF THE CORRESPONDING HEAD WITH SAID SLEEVE PORTION FIRMLY AND DIRECTLY FIXED, BY INTERFITTING MEANS, TO THE INSIDE OF SAID END OF THE BARREL, SAID ANNULAR FLANGE HAVING AN OUTER DIAMETER SUBSTANTIALLY GREATER THAN SAID BARREL TO REINFORCE SAID HEAD AGAINST RUPTURE BY HIGH STRESSES OF THE ENDS OF A FULL SQUARE PACKAGE OF STRETCHED YARN AGAINST SAID HED, SAID OUTER DIAMETER OF SAID ANNULAR FLANGE HAVING AN OUTWARDLY EXTENDING RIM FORMING AN OVERLAP OVER THE TOP OF A WASTE COLAR AT THE BASE OF A SPINDLE WHEN THE BOBBIN IS MOUNTED THEREON. 